Recherche d'indicateurs de la santé des sols

Soil is a finite and dynamic living resource. Soil health arises from multiple interactions between physicochemical and biological components, including microbial communities, of primary importance for soil functioning. Cultural practices have a strong influence on soil health, through both changes of physicochemical characteristics and influence on soil microbial communities. Cultural practices are thus more and more used for crop protection. In order to measure soil health and to propose cultural practices to improve it, it is necessary to define indicators of soil health. The aim of this study is to propose indicators of soil health, through the evaluation of the impact of two cultural practices (amendment with composted cattle manure amendment and biofumigation) on physicochemical and biological characteristics of the soil, in relation with the phytosanitary quality of a carrot crop. Multivariate analyses, associated with co-inertia analyses, revealed that some descriptors of the soil could be considered as potential indicators of soil health. In particular, these descriptors are associated with biofumigation, which enhance the soil suppressiveness to Rhizoctonia solani diseases. A population of Aspergillus fumigatus has also been showed to be preferentially associated with biofumigated soils. After this study, it is possible to propose descriptors which could be integrated in a minimum data set of indicators of soil health. This study could be continued by the confirmation of the interest of these descriptors, the construction of an indicator, and its validation.